Integrated modeling framework to evaluate conjunctive use options in a canal irrigated area

In canal irrigated areas, where interactions between surface water and groundwater are high, the conjunctive management of surface water and groundwater can play a significant role in improving water availability in time and space, thereby promoting more equitable distribution of water while maintaining long-term availability of groundwater resources. Achieving a harmonious balance between the use of surface water and groundwater requires careful consideration of the associated benefits, impacts, and trade-offs. In this study, a simple, integrated framework was developed and implemented to characterize and quantify interactions between surface water and groundwater in a canal irrigated area; this framework was used to evaluate the impacts of alternative levels of conjunctive use under varying climate and cropping conditions. Applying the model to a case study area of the Srisailam Right Branch Canal project in Andhra Pradesh, India, indicated that regulating canal supplies to optimum levels can prompt sustainable groundwater use and save up to 48% of allocated canal water; these water savings could be reallocated elsewhere within the irrigated area to promote equity.